Pod and Container Lifecycle (within a Pod)

Container Lifecycle (within a Pod)

Each container follows this:

1. Image Pull (if not present)
2. Created
3. Started
4. Running
5. Stopped (Exited) — success or failure
6. Restarted (if policy is Always or OnFailure)
7. Terminated

Pod Lifecycle Phases

1. Pending
   • Pod accepted by the API server, but not yet running on any node.
2. Scheduled
   • Pod has been assigned to a specific node by the scheduler.
3. Initialized
   • All initContainers have successfully completed (if any).
4. Running
   • Pod’s main containers are running or starting.
5. Ready
   • Pod has passed all readiness probes and is ready to serve traffic.
6. Succeeded
   • All containers completed successfully (exit code 0) — common for Jobs.
7. Failed
   • One or more containers exited with an error and won’t be restarted.
8. Unknown
   • The pod’s state can’t be determined (e.g., node crash/unreachable).
9. Terminating(transitional state)
   • Pod is being deleted; Kubernetes tries to shut it down gracefully.